Auto-refresh old post lists (with preference)

assets/changelog.txt

@@ -1,5 +1,6 @@
 75/1.9.6
 Multireddit viewing support
+Auto-refresh old post lists (with preference)
 Ability to view custom user pages
 Preference to hide Android status bar
 Preference to use un-shortened link for "Share Comments" (thanks to fhtagn)

src/main/java/org/quantumbadger/redreader/cache/downloadstrategy/DownloadStrategyIfTimestampOutsideBounds.java

@@ -0,0 +1,45 @@
+/*******************************************************************************
+ * This file is part of RedReader.
+ *
+ * RedReader is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * RedReader is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with RedReader.  If not, see <http://www.gnu.org/licenses/>.
+ ******************************************************************************/
+
+package org.quantumbadger.redreader.cache.downloadstrategy;
+
+import org.quantumbadger.redreader.cache.CacheEntry;
+import org.quantumbadger.redreader.common.TimestampBound;
+
+public class DownloadStrategyIfTimestampOutsideBounds implements DownloadStrategy {
+
+	private final TimestampBound mTimestampBound;
+
+	public DownloadStrategyIfTimestampOutsideBounds(final TimestampBound timestampBound) {
+		mTimestampBound = timestampBound;
+	}
+
+	@Override
+	public boolean shouldDownloadWithoutCheckingCache() {
+		return false;
+	}
+
+	@Override
+	public boolean shouldDownloadIfCacheEntryFound(final CacheEntry entry) {
+		return !mTimestampBound.verifyTimestamp(entry.timestamp);
+	}
+
+	@Override
+	public boolean shouldDownloadIfNotCached() {
+		return true;
+	}
+}

src/main/java/org/quantumbadger/redreader/common/General.java

@@ -229,6 +229,12 @@ public static boolean isConnectionWifi(final Context context){
 		return info != null && info.getDetailedState() == NetworkInfo.DetailedState.CONNECTED;
 	}
 
+	public static boolean isNetworkConnected(final Context context) {
+		final ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
+		final NetworkInfo activeNetworkInfo = cm.getActiveNetworkInfo();
+		return activeNetworkInfo != null && activeNetworkInfo.isConnected();
+	}
+
 	public static RRError getGeneralErrorForFailure(Context context, @CacheRequest.RequestFailureType int type, Throwable t, Integer status, String url) {
 
 		final int title, message;
@@ -576,4 +582,8 @@ public static void recreateActivityNoAnimation(final AppCompatActivity activity)
 		activity.overridePendingTransition(0, 0);
 		activity.startActivity(intent);
 	}
+
+	public static long hoursToMs(final long hours) {
+		return hours * 60L * 60L * 1000L;
+	}
 }

src/main/java/org/quantumbadger/redreader/common/PrefsUtility.java

@@ -492,6 +492,18 @@ public static void pref_cache_location(Context context,
 				.apply();
 	}
 
+	public static long pref_cache_rerequest_postlist_age_ms(final Context context, final SharedPreferences sharedPreferences) {
+		try {
+			final int hours = Integer.parseInt(
+					getString(R.string.pref_cache_rerequest_postlist_age_key, "1", context, sharedPreferences));
+
+			return General.hoursToMs(hours);
+
+		} catch(Throwable e) {
+			return 1;
+		}
+	}
+
 	// pref_cache_maxage
 
 	public static HashMap<Integer, Long> pref_cache_maxage(final Context context, final SharedPreferences sharedPreferences) {

src/main/java/org/quantumbadger/redreader/fragments/PostListingFragment.java

@@ -47,6 +47,7 @@
 import org.quantumbadger.redreader.cache.downloadstrategy.DownloadStrategy;
 import org.quantumbadger.redreader.cache.downloadstrategy.DownloadStrategyAlways;
 import org.quantumbadger.redreader.cache.downloadstrategy.DownloadStrategyIfNotCached;
+import org.quantumbadger.redreader.cache.downloadstrategy.DownloadStrategyIfTimestampOutsideBounds;
 import org.quantumbadger.redreader.cache.downloadstrategy.DownloadStrategyNever;
 import org.quantumbadger.redreader.common.AndroidApi;
 import org.quantumbadger.redreader.common.Constants;
@@ -222,6 +223,11 @@ public void onScrolled(final RecyclerView recyclerView, final int dx, final int
 		if(forceDownload) {
 			downloadStrategy = DownloadStrategyAlways.INSTANCE;
 
+		} else if(session == null && savedInstanceState == null && General.isNetworkConnected(context)) {
+
+			final long maxAgeMs = PrefsUtility.pref_cache_rerequest_postlist_age_ms(context, mSharedPreferences);
+			downloadStrategy = new DownloadStrategyIfTimestampOutsideBounds(TimestampBound.notOlderThan(maxAgeMs));
+
 		} else {
 			downloadStrategy = DownloadStrategyIfNotCached.INSTANCE;
 		}

src/main/java/org/quantumbadger/redreader/settings/SettingsFragment.java

@@ -32,7 +32,6 @@
 import android.preference.PreferenceFragment;
 import android.preference.PreferenceManager;
 import android.text.Html;
-
 import org.quantumbadger.redreader.BuildConfig;
 import org.quantumbadger.redreader.R;
 import org.quantumbadger.redreader.activities.ChangelogActivity;
@@ -96,7 +95,8 @@ public void onCreate(final Bundle savedInstanceState) {
 				R.string.pref_behaviour_screenorientation_key,
 				R.string.pref_behaviour_gallery_swipe_length_key,
 				R.string.pref_behaviour_pinned_subredditsort_key,
-				R.string.pref_behaviour_blocked_subredditsort_key
+				R.string.pref_behaviour_blocked_subredditsort_key,
+				R.string.pref_cache_rerequest_postlist_age_key
 		};
 
 		final int[] editTextPrefsToUpdate = {

src/main/res/values/arrays.xml

@@ -228,6 +228,8 @@
 
     <string-array name="pref_cache_maxage">
         <item>@string/time_1hr</item>
+		<item>@string/time_2hr</item>
+		<item>@string/time_3hr</item>
         <item>@string/time_6hr</item>
         <item>@string/time_1day</item>
         <item>@string/time_3day</item>
@@ -239,6 +241,8 @@
     <!-- Constants. Do not change. -->
     <string-array name="pref_cache_maxage_return">
         <item>1</item>
+		<item>2</item>
+		<item>3</item>
         <item>6</item>
         <item>24</item>
         <item>72</item>

src/main/res/values/strings.xml

@@ -919,4 +919,12 @@
 	<!-- 2016-09-21 -->
 	<string name="pref_appearance_show_blocked_subreddits_main_menu_key">pref_appearance_show_blocked_subreddits_main_menu</string>
 	<string name="pref_appearance_show_blocked_subreddits_main_menu_title">Show blocked subreddits in main menu</string>
+
+	<!-- 2016-10-02 -->
+	<string name="pref_cache_rerequest_postlist_age_key">pref_cache_rerequest_postlist_age</string>
+	<string name="pref_cache_rerequest_postlist_age_title">Refresh posts if cache older than</string>
+
+	<string name="time_2hr">2 hours</string>
+	<string name="time_3hr">3 hours</string>
+
 </resources>

src/main/res/xml/prefs_cache.xml

@@ -24,6 +24,12 @@
         <Preference android:title="@string/pref_cache_location_title"
                     android:key="@string/pref_cache_location_key"/>
 
+		<ListPreference android:title="@string/pref_cache_rerequest_postlist_age_title"
+						android:key="@string/pref_cache_rerequest_postlist_age_key"
+						android:entries="@array/pref_cache_maxage"
+						android:entryValues="@array/pref_cache_maxage_return"
+						android:defaultValue="1"/>
+
     </PreferenceCategory>
 
     <PreferenceCategory android:title="@string/pref_cache_precache_images_header">